The areas of investigation: 1. Cytogenetic studies of human neoplastic, hematological, and congenital disease, with special emphasis on patients with AIDS who develop leukemia, lymphoma, or Kaposi's sarcoma. Specific diseases studied include lymphoma (Burkitt's and non-Burkitt's), non-small cell carcinoma of the lung, ovarian cancer, Ewing's sarcoma, Askin's tumor, peripheral neuroepithelioma, esophogenal cancer, rhabdomyosarcoma, pheochromocytoma, and renal carcinoma. 2. In situ hybridization studies: a. Localization of c-oncogenes (c-myc, c-sis, etc) in the enoplastic cells (direct or tissue culture) of Burkitt's lymphoma (including AIDS), Ewing's sarcoma, and other cell lines. b. Localization of HTLV gene in patients with HTLV positive diseases; one patient with HTLV leukemia has been studied so far. c. Localization of the genes for DHFR in various HSR and double minute bearing tissue culture lines.